1889 Kumamoto earthquake

What Happened

At 23:40 Japan Standard Time on 28 July 1889 — 14:40 UTC — the ground beneath western Kumamoto began to move. The earthquake's magnitude was 6.3, and its epicentre lay at the south-eastern foot of Mount Kinpu, at coordinates 32.8°N, 130.7°E. Because the shaking struck at midnight, few houses caught fire; most people were asleep indoors rather than cooking or using lamps.

The death toll was twenty. Five of the dead were in Kumamoto City, and fifteen were in Akita Gun, a district of Kumamoto Prefecture. Hundreds of houses were destroyed, and parts of Kumamoto Castle — the great fortress at the centre of the city — came down as well.

Aftershocks continued for five months. With their homes unsafe, some residents slept outdoors for extended periods. The earthquake's seismic waves travelled far enough to be recorded in Potsdam, Germany, on instruments there.

Background

The earthquake fell in the twenty-second year of the Meiji era, during the reign of the Meiji period (1868–1912). Japan was in the middle of a rapid programme of modernisation, and one of its products was the Seismological Society of Japan, founded in 1880. The 1889 Kumamoto earthquake was the first major earthquake to strike after that society was established.

That timing mattered for how the event was documented. Photographs taken of the damage in Kumamoto are considered the earliest earthquake damage photographs made in Japan. The quake therefore sits at the boundary between an older Japan known through written chronicles and a modern Japan that could record its disasters on film and on instruments.

The epicentral region around Mount Kinpu was geologically notable. The seismologist Tadao Shimoma argued that the earthquake resulted from a combination of the Tatsuda fault and unsuccessful volcanic activity, citing injections of aerosol into the air at many places around Mount Kinpo, Ninotake and Sannotake. He also claimed that the Kinpo mountains, which show no volcanic activity today, resemble Mount Unzen in petrology.

Why It Mattered

Three things set this earthquake apart. The first is the record it left. Because the Seismological Society of Japan had been founded nine years earlier, the event was studied by an organised scientific community rather than only described in official reports. Its waves reached Potsdam, giving researchers in Europe a data point from a Japanese earthquake.

The second is the photographic record. The images made in Kumamoto after 28 July 1889 are regarded as the earliest photographs of earthquake damage taken in Japan. That makes the event a starting point for a visual tradition that would document Japanese earthquakes for the following century and more.

The third is the human cost and its distribution. Twenty deaths — five in Kumamoto City and fifteen in Akita Gun — show that the destruction was not confined to the urban centre. Kumamoto Castle, the most prominent structure in the city, was partly destroyed, and hundreds of houses were lost. The five months of aftershocks kept survivors outside their homes long after the initial shock.

The Name in Japanese

The Japanese name of the event is 熊本地震, read くまもとじしん in kana and written Kumamoto jishin in romaji. It is the ordinary modern Japanese way of naming an earthquake: the place name, followed by the word for earthquake.

Breaking it down character by character:

熊 — read くま (kuma) in this word. It means "bear". This character is the first element of the place name Kumamoto. It is a common kanji, and its reading here is the native Japanese word for bear rather than a Chinese-derived reading.

本 — read もと (moto) in this word. Its basic meaning is "origin", "base" or "book", depending on context. Here it is the second element of the place name Kumamoto. The combination 熊本 literally suggests "bear origin" or "bear base", though as a place name it simply identifies the city and prefecture on the island of Kyushu.

地 — read じ (ji) in this word. It means "earth", "ground" or "land". It is the first element of the compound for earthquake.

震 — read しん (shin) in this word. It means "shake" or "tremor". Combined with 地, it forms 地震 (じしん, jishin), the standard Japanese word for "earthquake" — literally "earth shake".

The full name 熊本地震 therefore parses as "Kumamoto" plus "earthquake". Note that the character 震 also appears in 震度 (shindo), the Japanese scale of seismic intensity, and in 余震 (yoshin), "aftershock" — a word that would have been in daily use in Kumamoto for the five months following 28 July 1889.

Key Figures

Tadao Shimoma — the seismologist who proposed that the 1889 earthquake combined the action of the Tatsuda fault with unsuccessful volcanic activity. He based this on reports of aerosol injections into the air at many places around Mount Kinpo, Ninotake and Sannotake, and on a petrological comparison between the Kinpo mountains and Mount Unzen.

The Seismological Society of Japan — founded in 1880, nine years before the earthquake. Its existence meant that the 1889 event was the first major Japanese earthquake to occur within an organised scientific framework, and its waves were recorded as far away as Potsdam, Germany.

The people of Kumamoto City and Akita Gun — twenty dead, five in the city and fifteen in the district. Hundreds of houses were destroyed, parts of Kumamoto Castle fell, and aftershocks forced survivors to sleep outdoors for months.